Peggy Whitson, Astronaut

Without much fanfare, NASA astronaut Peggy Whitson will return to Earth on Saturday night—it will be Sunday morning on the steppes of Kazakhstan—aboard a Soyuz spacecraft. Quietly, she will have spent 288 days in space, or nearly 10 months. …

Whitson is known around NASA’s Johnson Space Center as perhaps the agency’s most efficient astronaut in space, regularly getting ahead of her timelines, research, and maintenance tasks for each day. Mission controllers typically have to come up with extra work. Partly because of this, she is one of only a handful of NASA astronauts to have been selected to serve three rotations on the International Space Station.

As a result of these three long duration spaceflights, the biochemist has now logged 665 days in space. This cumulative time in space easily ranks her as the American flier with the most experience in orbit, far above the 534 days tallied by NASA’s Jeff Williams and 520 days of Scott Kelly. …

Those aren’t all of her accolades, either. In 2008, Whitson became the first female commander of the International Space Station. She is also the oldest woman, aged 57, to fly. And with 10 spacewalks totaling more than 60 hours, she ranks as the third most accomplished spacewalker.